1. Field of the Invention
The present invention relates to a radio transmission system.
2. Description of the Background Art
In a radio transmission system for a digital video signal, a transmitter stores in a buffer a packet generated by a coding device, and outputs data representing the packet stored in the buffer for each predetermined time period, and a receiver receives a packet to be received, and then immediately outputs the received packet to a decoding device. In the radio transmission system, it has been known that a packet output interval in the coding device and a packet input interval in the receiver differ. Such a phenomenon is referred to as jitter.
Furthermore, in a radio communication transmission path, a transmission error may occur. In a case where an error occurs in the received packet, the receiver issues a retransmission request to the transmitter, and the transmitter which has received the retransmission request retransmits the same packet. If such retransmission is made, the jitter is further increased.
In an MPEG (Moving Picture Experts Group) 2 system frequently utilized in transmission of a digital video/audio signal, when jitter produced by the transmission is increased, overflow or underflow occurs in a buffer in the decoding device, so that video/audio cannot be normally reproduced.